/** 
 *  Copyright 2010 Matthew Werny & Burk Price.
 * 
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 * 
 *       http://www.apache.org/licenses/LICENSE-2.0
 * 
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *  under the License.
 */
package net.iceflow.db.migration;

import java.util.SortedSet;

/**
 * @version 1.0
 */
public interface MigrationManager {

	/**
	 * Validates whether the database is currently up-to-date.
	 * @return true if the database is up-to-date, false if it is not or is unversioned
	 */
	boolean validate();

	/**
	 * Returns a sorted set of pending migrations, in the order that they would be run if a migration was performed.
	 *
	 * @return a sorted set of pending migrations, or an empty set if there are none pending
	 */
	SortedSet<MigrationExecuter> pendingMigrations();

	/**
	 * Migrates the database to the latest version, enabling migrations if necessary.
	 */
	void migrate();
}
